1. Field of the Invention
The invention relates to fiber-optic connector inspection microscopes and more particularly to an adaptive device for shifting the imaging axis of a microscope across the endfaces of a multi-fiber connector for inspecting the fiber-optic endfaces through the microscope.
2. Description of the Related Art
The widespread implementation of fiber-optic communications for high-density interconnections has driven more and more multi-fiber connectors to be adopted in the industry. This creates an urgent need for regularly inspecting and maintaining the multi-fiber connectors in place, which are often situated behind backplanes or in locations which are very difficult to access.
It is well known in the fiber-optic communication industry that the endfaces of optical fibers within communication systems must be kept clean and undamaged, otherwise serious signal loss could result. The demand for cleanliness for fiber-optic endfaces has become even more stringent as the communication bandwidths increase and new communication technology requiring higher laser power is applied.
Many types of microscopes are already available for inspecting the endface of a fiber-optic connector to make sure the endface is undamaged and clean. Due to the need for sufficient magnification, the fiber-optic endface is typically inspected only one at a time. For example, the endface with a typical diameter of 0.125 mm can be inspected with a microscope with a field of view of about 0.3 mm×0.4 mm only one at a time. For a multi-fiber connector, with the centers of the fiber-optic endfaces spaced typically at 0.25 mm, the microscope must be able to scan from one side to the other side of the connector in order to inspect each of the fiber-optic endfaces. Therefore an adaptive device is needed to bring the fiber-optic endfaces one by one within the field of view of the microscope for inspection.
Cassady (U.S. Pat. Nos. 6,751,017 and 6,879,439) discloses a microscope for inspecting fiber-optic endfaces in a multi-fiber connector. The microscope comprises a tip capable of interfacing with the multi-fiber connector, a slider assembly, a slider chassis and a drive assembly, in which the driver assembly interfaced with the slider assembly is capable of selectively displacing the slider chassis along an axis of motion to selectively direct the imaging axis of the microscope between adjacent fiber-optic endfaces.
Zhou et al. (U.S. Pat. No. 7,336,884) discloses a different device for inspecting the fiber-optic endfaces through the microscope. The device comprises a supporting body; a pendular arm rotatably mounted to the supporting body; a fitting tip attached to the pendular arm allowing the imaging axis of the microscope to pass therethrough; and a bevel wheel fastened to the supporting body. The bevel wheel is adapted to swing the pendular arm relative to the supporting body so that the imaging axis of the microscope is moved relative to the fitting tip to selectively align the imaging axis between adjacent fiber-optic endfaces for inspection. However, with this device, the imaging axis of the microscope moves along a circular track relative to the fitting tip and as a result the imaging axis cannot be aligned with and focused on the center of every endface in a multi-fiber connector—since the endfaces in a multi-fiber connector are almost always arranged in a straight line.
Therefore, another design for the multi-fiber inspecting device is needed, wherein the imaging axis of the microscope is moved relative to the fitting tip in a straight line, so that the imaging axis can be adapted to align with the center of each and every endface in a multi-fiber connector.